US6353694B1 - MMI thermo-optic coupler - Google Patents

MMI thermo-optic coupler Download PDF

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US6353694B1
US6353694B1 US09/556,188 US55618800A US6353694B1 US 6353694 B1 US6353694 B1 US 6353694B1 US 55618800 A US55618800 A US 55618800A US 6353694 B1 US6353694 B1 US 6353694B1
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cladding
coupler
core
light
input port
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Reza Paiam
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Lumentum Ottawa Inc
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Lumentum Ottawa Inc
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    • G02B6/3564Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3576Temperature or heat actuation
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    • G02B6/2808Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using a mixing element which evenly distributes an input signal over a number of outputs
    • G02B6/2813Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using a mixing element which evenly distributes an input signal over a number of outputs based on multimode interference effect, i.e. self-imaging
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    • G02B6/29379Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
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    • G02B6/12Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
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Definitions

  • This invention relates to a multi-mode (MMI) coupler, and more particularly to an MMI coupler having a polymer cladding.
  • MMI multi-mode
  • optical signals are transmitted by means of optical signals through otpical fibers.
  • the optical signals are processed on integrated optical chips which are placed between the fibers.
  • support substrates such as, for example glass, Si, InP, GaAs and subsequently structured.
  • the light is guided through a medium referred to as the waveguide core.
  • the waveguide core is bounded by a reflecting transition.
  • a metal is used for this purpose.
  • dielectric waveguides the total reflection on a surrounding medium having a smaller refractive index the waveguide cladding is used.
  • optical waveguides only those modes can propagate which fulfil the Maxwell equations.
  • the waveguides are referred to as cut-off, monomode or multimode waveguides, dependent on whether they can guide no mode, only one mode for each polarization or a plurality of modes.
  • the light propagates in the longitudinal z direction.
  • the x direction is parallel to the waveguide layer and is defined as the horizontal, or lateral direction.
  • the y direction is vertical to the waveguide layer and is defined as the vertical, or transversal direction.
  • the propagation of light on the chips is computed by means of numerical methods such as beam propagation (BPM) methods, or modal propagation analysis (MPA) methods.
  • BPM beam propagation
  • MPA modal propagation analysis
  • semi-analytical computations such as the effective index method (EIM) are used.
  • EIM effective index method
  • the Maxwell equations are often solved in a scalar approximation. These equations describe the planar optics exactly.
  • Two polarizations can be distinguished: the TE polarization has the E vector in the x direction.
  • the TM polarization has the H vector in the x direction.
  • the scalar approximation leads to “quasi-TE” and “quasi-TM” modes.
  • the mode forms and the “effective” indexes may be dependent on the polarization.
  • “monomode” waveguides often have a mode for each polarization, i.e. overall, there are often two modes in “monomode” waveguides. These are degenerate modes in normal optical glass fibers.
  • N ⁇ M splitters Important components in integrated optics are the beam splitters and combiners. Generally, one refers to N ⁇ M splitters. N ⁇ M denote the number of inputs and outputs. Ideally, these splitters should have the following properties: they should be compact (having small dimensions), independent of polarization, not very sensitive to manufacturing inaccuracies and easy to produce. Moreover, it should be possible to readily adapt the splitting or combining ratios to the various applications by geometrical changes in the design.
  • Various beam splitters and combiners have already been realised: Symmetrical Y branches are simple solutions for 1 ⁇ 2 splitters with a 50%/50% intensity ratio. Asymmetrical Y branches yield other intensity ratios but, due to coupling effects, they are often polarization-dependent between the two outputs. For manufacturing Y branches, a high resolution, particularly in the sharp bifurcation, is required. They are very sensitive to manufacturing inaccuracies.
  • Directional couplers with two parallel waveguides separated by means of a narrow slit operate as 2 ⁇ 2 splitters.
  • the coupling length is, however, very sensitive to manufacturing parameters, particularly as regards slit width and depth.
  • the coupling length is also very much dependent on polarization.
  • “Two-mode” interference (TMI) couplers without a slit also operate as 2 ⁇ 2 splitters.
  • the intensity ratio is, however, very much dependent on the coupling into the input and output Y branches. Consequently, they are very sensitive to manufacturing conditions.
  • U.S. Pat. No. 5,857,039 describes a thermo-optically activated directional coupler having a polymer guide buffer layer and a heater which allows the refractive index of the polymer to be varied.
  • the '039 patent extols the virtues of polymer over silica especially in the interguide space.
  • the guides can only be properly covered by the mineral layer, particularly in the case of silica coverings, by a so-called “FHD” technique which is extremely difficult to apply. Therefore, the '039 patent provides a solution which is tailored to providing a more practicably directional coupler.
  • a polymer cladding on an silica filament strand of optical fibre is well known, and has been disclosed in U.S. Pat. No. 4,116,654 issue Sep. 26, 1978. In this patent it is stated that “Where low attenuation of transmitted light in an optical fiber material is critical, the preferred material for the filamentary core is silica, since it has one of the lowest attenuations presently known.
  • Suitable cladding materials known in the art include thermoplastic polymers which have an index of refraction lower than that of the core; and which preferably are substantially amorphous.”
  • the cladding guides the light within a waveguide or optical fibre and when the relative refractive index difference between the cladding and the core is varied the confinement of light within a guide varies as well.
  • MMI couplers have become more and more popular. These components are waveguide sections guiding a plurality of modes. They are produced, for example by widening a conventional waveguide structure until it guides a sufficient number of modes. The lateral guidance is then, for example, also often increased. Thanks to their self-imaging property, these couplers operate as N ⁇ M splitters in two or three dimensions. “Conventional” MMI couplers as used throughout the specification and the following claims are understood to be those elements having parallel sides. It is to be noted that MMI couplers can also be made with slanting sides. Several prior art patents describe the function and operation of the MMI couplers, such as U.S. Pat. No.
  • MMI couplers have been very difficult to manufacture with a great deal of accuracy. Notwithstanding, since these devices are not highly tolerant to imperfect manufacturing, producing MMI couplers has been a feat, and until now, has remained a costly process.
  • the invention discovered here concerns providing a polymer layer atop the MMI wide core and lessens the requirement for accuracy in manufacturing and allows a device to be tuned to meet required specifications, within predetermined limits. For example, a poorly manufactured device can be tuned to perform as a perfectly manufactured device that meets its original specifications. Hence, many fewer devices are rejected and discarded as rejects.
  • a second advantage of this invention is that devices can be tuned to provide a controlled and variable output.
  • the MMI coupler can function as a switch or a variable coupler.
  • a multi-mode interference coupler for coupling light between ports, comprising:
  • a first input port for launching light into a core of a substantially planar waveguide of a first material having a first refractive index n 1 , the substantially planar waveguide having a response that confines the light to a single mode in one dimension, and multi-mode in another dimension;
  • At least two output ports for receiving light launched into and propagating through the core from the input port
  • a heater thermally coupled to said cladding for heating the cladding in dependence upon a control signal, to vary at least one of
  • At least one of the first material and the second material is a polymer.
  • FIG. 1 a is a top view of an MMI-based thermo-optic switch/attenuator
  • FIG. 1 b is a cross-section of the device having a polymer cladding
  • FIG. 2 is a typical plot of the ratio W e /W of a MMI coupler against the refractive index of the cladding, wherein the refractive index of the core has been kept fixed at 1.5.
  • thermo-optic optical switch or attenuator in the form of an MMI couplers as shown.
  • the MMI coupler has two input ports and two output ports. Alternatively one input port can be provided.
  • This device can be used as a switch or an attenuator. Switching is done by changing the temperature of the device through the heating element placed on top of the device. Alternatively, the same thermo-optic effect can be used to initially compensate for the fabrication variations of the coupler.
  • ⁇ 0 and ⁇ 1 are the propagation constants of the fundamental and first order modes, respectively
  • n ver is the slab effective index at the guiding region
  • W e is the effective width of the fundamental transverse mode.
  • the effective width (W e ) is slightly larger than the actual width (W) of the multimode waveguide and takes into account the lateral penetration depth of the modal field.
  • the effective width depends on the waveguide characteristics. It can be approximated by the effective width of the fundamental mode and is given by W e ⁇ W + ( ⁇ ⁇ ) ⁇ ( n 2 n 1 ) 2 ⁇ ⁇ ⁇ ( n 1 2 - n 2 2 ) - ( 1 / 2 ) ( 2 )
  • n 1 and n 2 are the refractive indices of the core and cladding, respectively.
  • n ver and/or W e can be varied. As indicated in Equation (1), the beatlength is directly dependent on the square of W e and, therefore, varying W e rather than n ver has much more pronounced effect on the beatlength.
  • W e can be changed by varying the index contrast between the core and cladding of the waveguide. If core and cladding have similar themo-optic coefficients (dn/dT), then we can only change n ver and not W e by changing the temperature of the device. However, If the core and cladding of the waveguides are selected to have suitable refractive indices and of different materials with different thermo-optic coefficients, then the effective width W e can be altered by changing the temperature.
  • FIG. 2 illustrates a variation of the ratio W e /W against the changes of the refractive index of the cladding for a given MMI coupler. It can be seen that the rate of change of the ratio W e /W is faster as the refractive indices of the core and cladding become close together. This is evident from Equation (2) wherein the difference between W e and W gets smaller for waveguide with higher contrast (i.e., larger difference between n 1 and n 2 ).
  • the effective width of the MMI coupler can be changed efficiently by varying the refractive index of either the core or the cladding, while keeping the other one relatively unchanged. This method is much more effective than changing n ver .
  • the parameter values shown in the following table show a design example.
  • a change of 0.01 in the refractive index value of the cladding is required for the switching operation.
  • the required change in the temperature of the device for 0.01 change in refractive index of the cladding is about 40 degrees Centigrade.
  • the coupler length is about 670 ⁇ m.
  • An extinction ratio of more than 20 dB can be easily achieved.
  • the device has a wide bandwidth.

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Abstract

A multi-mode interference coupler is disclosed for coupling light between ports. The MMI coupler is a planar waveguide having a first input port for launching light into a core of the planar waveguide which has first refractive index n1. The waveguide is dimensioned to have a response that confines light launched therein to a single mode in one dimension, and multi-mode in another dimension. Two other ports are provided for receiving light launched into and propagating through the core from the input port. A polymer cladding of a second material having a refractive index n2 covers at least a portion of the core. A heater is provided and is thermally coupled to the cladding for heating the cladding when a control signal is applied.

Description

FIELD OF THE INVENTION
This invention relates to a multi-mode (MMI) coupler, and more particularly to an MMI coupler having a polymer cladding.
BACKGROUND OF THE INVENTION
In the processing of light beams for example, in telecommunications applications, important and desired functions are the splitting and combining of light beams. In conventional optics, prisms or pellicle splitters are used for this purpose. Attempts are continually being made to reduce the dimensions of the optical components to a considerable extent. On the one hand, it is being attempted in three dimensions to realise the processing of light beams by means of interference phenomena such as holography and free space optics. On the other hand, the technique of integrated optics is developing very rapidly. In this technique, waveguides are patterned on thin-film layers. It is an object of integrated optics to realise the functionality of the components used in conventional optics by new, integrable optical elements. This research field has found important applications in the field of communication.
In fiber-optical communication, data are transmitted by means of optical signals through otpical fibers. The optical signals are processed on integrated optical chips which are placed between the fibers. To manufacture these chips, generally thin-film layers are provided on support substrates such as, for example glass, Si, InP, GaAs and subsequently structured.
In optical waveguides the light is guided through a medium referred to as the waveguide core. The guidance is realised in that the waveguide core is bounded by a reflecting transition. In cavity waveguides, a metal is used for this purpose. In dielectric waveguides, the total reflection on a surrounding medium having a smaller refractive index the waveguide cladding is used. In optical waveguides, only those modes can propagate which fulfil the Maxwell equations. The waveguides are referred to as cut-off, monomode or multimode waveguides, dependent on whether they can guide no mode, only one mode for each polarization or a plurality of modes.
In waveguides, the light propagates in the longitudinal z direction. The x direction is parallel to the waveguide layer and is defined as the horizontal, or lateral direction. Analogously, the y direction is vertical to the waveguide layer and is defined as the vertical, or transversal direction. The propagation of light on the chips is computed by means of numerical methods such as beam propagation (BPM) methods, or modal propagation analysis (MPA) methods. In some cases, semi-analytical computations such as the effective index method (EIM) are used. The Maxwell equations are often solved in a scalar approximation. These equations describe the planar optics exactly. Two polarizations can be distinguished: the TE polarization has the E vector in the x direction. and the TM polarization has the H vector in the x direction. For the most frequently used dielectric waveguides in integrated optics, the scalar approximation leads to “quasi-TE” and “quasi-TM” modes. In such waveguides, the mode forms and the “effective” indexes may be dependent on the polarization. In many cases it is very much desirable, but very difficult, to produce components which are independent of polarization. It should be noted that “monomode” waveguides often have a mode for each polarization, i.e. overall, there are often two modes in “monomode” waveguides. These are degenerate modes in normal optical glass fibers.
Important components in integrated optics are the beam splitters and combiners. Generally, one refers to N×M splitters. N×M denote the number of inputs and outputs. Ideally, these splitters should have the following properties: they should be compact (having small dimensions), independent of polarization, not very sensitive to manufacturing inaccuracies and easy to produce. Moreover, it should be possible to readily adapt the splitting or combining ratios to the various applications by geometrical changes in the design. Various beam splitters and combiners have already been realised: Symmetrical Y branches are simple solutions for 1×2 splitters with a 50%/50% intensity ratio. Asymmetrical Y branches yield other intensity ratios but, due to coupling effects, they are often polarization-dependent between the two outputs. For manufacturing Y branches, a high resolution, particularly in the sharp bifurcation, is required. They are very sensitive to manufacturing inaccuracies.
Directional couplers with two parallel waveguides separated by means of a narrow slit operate as 2×2 splitters. However the coupling length is, however, very sensitive to manufacturing parameters, particularly as regards slit width and depth. The coupling length is also very much dependent on polarization. “Two-mode” interference (TMI) couplers without a slit also operate as 2×2 splitters. The intensity ratio is, however, very much dependent on the coupling into the input and output Y branches. Consequently, they are very sensitive to manufacturing conditions. U.S. Pat. No. 5,857,039 describes a thermo-optically activated directional coupler having a polymer guide buffer layer and a heater which allows the refractive index of the polymer to be varied. Of course it is well known that polymer has a higher refractive index variation with temperature than silica and better heat confinement. The '039 patent extols the virtues of polymer over silica especially in the interguide space. When the interguide space is small in relation to the dimensions of the cross section, the guides can only be properly covered by the mineral layer, particularly in the case of silica coverings, by a so-called “FHD” technique which is extremely difficult to apply. Therefore, the '039 patent provides a solution which is tailored to providing a more practicably directional coupler.
It is somewhat obvious, in hindsight, that in a directional coupler wherein coupling of light across a cladding boundary between two closely spaced waveguides is to be accomplished, that the boundary region must be controlled to increase or decrease the coupling across this region. Ergo, in order to allow the two single mode signals to couple, or to remain isolated, in a controlled manner, this intermediary cladding region must be highly manufacturable and controllable. As the '039 patent purports, a polymer disposed between these cores, provides a practicable solution.
The use of a polymer cladding on an silica filament strand of optical fibre is well known, and has been disclosed in U.S. Pat. No. 4,116,654 issue Sep. 26, 1978. In this patent it is stated that “Where low attenuation of transmitted light in an optical fiber material is critical, the preferred material for the filamentary core is silica, since it has one of the lowest attenuations presently known. Suitable cladding materials known in the art include thermoplastic polymers which have an index of refraction lower than that of the core; and which preferably are substantially amorphous.”
A further mention of polymer cladding is found in U.S. Pat. No. 5,873,923 in the name of DiGiovanni, with reference to optical amplifiers.
In this patent, a polymer cladding is suggested in a multi-clad fibre amplifier, where the 923 patent states that “Any polymer cladding serves little purpose beyond guiding”.
Considering the teaching of DiGiovanni, and that of U.S. Pat. No. 5,857,039, it is evident that the cladding guides the light within a waveguide or optical fibre and when the relative refractive index difference between the cladding and the core is varied the confinement of light within a guide varies as well.
What is surprising however, is that significance of providing a cladding on a multi-mode coupler which operates under a very different regime. What is further surprising is how coupling within a wide MMI core is affected by varying the cladding on top. Notwithstanding, this will be explained.
In the last few years, multimode interference (MMI) couplers have become more and more popular. These components are waveguide sections guiding a plurality of modes. They are produced, for example by widening a conventional waveguide structure until it guides a sufficient number of modes. The lateral guidance is then, for example, also often increased. Thanks to their self-imaging property, these couplers operate as N×M splitters in two or three dimensions. “Conventional” MMI couplers as used throughout the specification and the following claims are understood to be those elements having parallel sides. It is to be noted that MMI couplers can also be made with slanting sides. Several prior art patents describe the function and operation of the MMI couplers, such as U.S. Pat. No. 5,698,597 in the name of Besse, issued Nov. 18, 1997, and U.S. Pat. No. 5,953,467 in the name of Madsen issued Sep. 14, 1999, both incorporated herein by reference. Since the invention deals exactly with this point, it is necessary to elucidate the properties of the “conventional” MMI couplers.
Heretofore, MMI couplers have been very difficult to manufacture with a great deal of accuracy. Notwithstanding, since these devices are not highly tolerant to imperfect manufacturing, producing MMI couplers has been a feat, and until now, has remained a costly process. The invention discovered here concerns providing a polymer layer atop the MMI wide core and lessens the requirement for accuracy in manufacturing and allows a device to be tuned to meet required specifications, within predetermined limits. For example, a poorly manufactured device can be tuned to perform as a perfectly manufactured device that meets its original specifications. Hence, many fewer devices are rejected and discarded as rejects.
A second advantage of this invention is that devices can be tuned to provide a controlled and variable output. For example, the MMI coupler can function as a switch or a variable coupler.
In hindsight, after considering this invention, it is not intuitive, since multi-modes are mixed with a single wide guide having confinement only in the vertical dimension wherein the modes are “essentially” free to mix in a lateral dimension; thus it is quite surprising that the discovery of the provision of a polymer confining layer over top of the single multi-mode guide would yield any significant advantage.
Notwithstanding, best mode working embodiments will be described.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an MMI coupler that is tunable and that is more tolerant to manufacturing inaccuracies due to its tunability.
In accordance with the invention a multi-mode interference coupler for coupling light between ports is provided, comprising:
a first input port for launching light into a core of a substantially planar waveguide of a first material having a first refractive index n1, the substantially planar waveguide having a response that confines the light to a single mode in one dimension, and multi-mode in another dimension;
at least two output ports for receiving light launched into and propagating through the core from the input port;
a polymer cladding of a second material having a refractive index n2 covering at least a portion of the core; and,
a heater thermally coupled to said cladding for heating the cladding in dependence upon a control signal, to vary at least one of
a) the amount of light received at the at least two output ports and,
b) the ratio of light distributed between the output ports,
wherein at least one of the first material and the second material is a polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention will now be described in conjunction with the drawings in which:
FIG. 1a is a top view of an MMI-based thermo-optic switch/attenuator;
FIG. 1b is a cross-section of the device having a polymer cladding;
FIG. 2 is a typical plot of the ratio We/W of a MMI coupler against the refractive index of the cladding, wherein the refractive index of the core has been kept fixed at 1.5.
DETAILED DESCRIPTION
Referring now to FIGS. 1a and 1 b, a thermo-optic optical switch or attenuator in the form of an MMI couplers as shown. The MMI coupler has two input ports and two output ports. Alternatively one input port can be provided. This device can be used as a switch or an attenuator. Switching is done by changing the temperature of the device through the heating element placed on top of the device. Alternatively, the same thermo-optic effect can be used to initially compensate for the fabrication variations of the coupler.
A most important parameter in the design of MMI couplers is their beatlength, Lπ. After fabrication of a device, tuning and switching can be performed by varying its beatlength. For MMI couplers, the beat length at a wavelength λ0 is defined as L π = π β 0 - β 1 4 n ver W e 2 3 λ 0 , ( 1 )
Figure US06353694-20020305-M00001
where β0 and β1 are the propagation constants of the fundamental and first order modes, respectively, nver is the slab effective index at the guiding region, and We is the effective width of the fundamental transverse mode. The effective width (We) is slightly larger than the actual width (W) of the multimode waveguide and takes into account the lateral penetration depth of the modal field. The effective width depends on the waveguide characteristics. It can be approximated by the effective width of the fundamental mode and is given by W e W + ( λ π ) ( n 2 n 1 ) 2 σ ( n 1 2 - n 2 2 ) - ( 1 / 2 ) ( 2 )
Figure US06353694-20020305-M00002
where σ=0 for TE, σ=1 for TM, and n1and n2 are the refractive indices of the core and cladding, respectively.
To change the beatlength, nver and/or We can be varied. As indicated in Equation (1), the beatlength is directly dependent on the square of We and, therefore, varying We rather than nver has much more pronounced effect on the beatlength. We can be changed by varying the index contrast between the core and cladding of the waveguide. If core and cladding have similar themo-optic coefficients (dn/dT), then we can only change nver and not We by changing the temperature of the device. However, If the core and cladding of the waveguides are selected to have suitable refractive indices and of different materials with different thermo-optic coefficients, then the effective width We can be altered by changing the temperature.
FIG. 2 illustrates a variation of the ratio We/W against the changes of the refractive index of the cladding for a given MMI coupler. It can be seen that the rate of change of the ratio We/W is faster as the refractive indices of the core and cladding become close together. This is evident from Equation (2) wherein the difference between We and W gets smaller for waveguide with higher contrast (i.e., larger difference between n1 and n2). Thus, if the MMI coupler is weakly confining, the effective width of the MMI coupler can be changed efficiently by varying the refractive index of either the core or the cladding, while keeping the other one relatively unchanged. This method is much more effective than changing nver.
EXEMPLARY EMBODIMENT
The parameter values shown in the following table show a design example. A change of 0.01 in the refractive index value of the cladding is required for the switching operation. Assuming a dn2/dT=2.5* 10−4/K, which is a typical value for polymers, the required change in the temperature of the device for 0.01 change in refractive index of the cladding is about 40 degrees Centigrade. The coupler length is about 670 μm. An extinction ratio of more than 20 dB can be easily achieved. The device has a wide bandwidth.
MMI in/out guides
Width 8 μm 3 μm ncore = 1.50 Lπ,1 = 167.5 μm
# of modes 2/3 1 nclad,1 = 1.49 Lπ,2 = 133.5 μm
nclad,2 = 1.48
Of course, numerous other embodiments may be envisaged, without departing from the spirit and scope of the invention.

Claims (5)

What is claimed is:
1. A multi-mode interference coupler for coupling light between ports, comprising:
a first input port for launching light into a core of a substantially planar waveguide of a first material having a first refractive index n1, the substantially planar waveguide having a response that confines the light to a single mode in one dimension, and multi-mode in another dimension;
at least two output ports for receiving light launched into and propagating through the core from the input port;
a polymer cladding of a second material having a refractive index n2 covering at least a portion of the core; and,
a heater thermally coupled to said cladding for heating the cladding in dependence upon a control signal, to vary at least one of
a) the amount of light received at the at least two output ports and,
b) the ratio of light distributed between the output ports,
wherein at least one of the first material and the second material is a polymer.
2. A coupler for coupling as defined in claim 1, wherein the first material is a non-polymer.
3. A coupler as defined in claim 2, wherein first material is glass.
4. A coupler as defined in claim 3 further wherein the MMI coupler is a thermo-optic switch, splitter, or attenuator and wherein the first input port is at a first end and wherein the at least two output ports are at a second end.
5. A coupler as defined in claim 2, further comprising a second input port, adjacent the first input port.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003016957A2 (en) * 2001-08-16 2003-02-27 Srinath Kalluri Index tuned multimode interference coupler
WO2003016988A1 (en) * 2001-08-16 2003-02-27 Scott David C Optical modulator with an index tuuned multimode splitter
US6600848B2 (en) * 2000-08-02 2003-07-29 Corning Incorporated Integrated thermo-optical silica switch
US20040101245A1 (en) * 2002-11-27 2004-05-27 Nec Tokin Corporation Variable optical attenuator
US20070147761A1 (en) * 2005-10-07 2007-06-28 Kwakernaak Martin H Amorphous silicon waveguides on lll/V substrates with barrier layer
US20130230320A1 (en) * 2012-03-05 2013-09-05 Alcatel-Lucent Usa, Inc. Flexible optical modulator for advanced modulation formats featuring asymmetric power splitting
US8867874B2 (en) * 2012-12-06 2014-10-21 Finisar Sweden Ab Method for modifying the combining or splitting ratio of a multimode interference coupler
US20140334775A1 (en) * 2013-05-07 2014-11-13 Sumitomo Electric Industries, Ltd Coherent mixer and 2x2 multi-mode interference coupler
JP7031082B1 (en) * 2021-06-04 2022-03-07 三菱電機株式会社 Semiconductor optical integrated device and optical integrated device

Families Citing this family (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6571038B1 (en) * 2000-03-01 2003-05-27 Lucent Technologies Inc. Multimode interference coupler with tunable power splitting ratios and method of tuning
EP1182472B1 (en) * 2000-08-23 2006-04-05 Matsushita Electric Industrial Co., Ltd. Optical element and method of fabrication thereof
US6456429B1 (en) * 2000-11-15 2002-09-24 Onetta, Inc. Double-pass optical amplifier
US6538816B2 (en) * 2000-12-18 2003-03-25 Jds Uniphase Inc. Micro-electro mechanical based optical attenuator
US6714575B2 (en) * 2001-03-05 2004-03-30 Photodigm, Inc. Optical modulator system
JP2003005232A (en) * 2001-04-18 2003-01-08 Ngk Insulators Ltd Optical device
US6621971B2 (en) * 2001-06-20 2003-09-16 Jds Uniphase Photonics Gmbh & Co. Waveguide structure
US6618519B2 (en) * 2001-07-16 2003-09-09 Chromux Technologies, Inc. Switch and variable optical attenuator for single or arrayed optical channels
US6865315B2 (en) * 2001-08-29 2005-03-08 Jds Uniphase Corporation Dispersion compensating filters
US6836610B2 (en) * 2001-09-07 2004-12-28 Hon Hai Precision Ind. Co., Ltd. Electrical variable optical attenuator
JP3530840B2 (en) * 2001-10-10 2004-05-24 サンテック株式会社 Variable wavelength splitter, variable wavelength multiplexer, and wavelength routing device
JP2003131055A (en) * 2001-10-25 2003-05-08 Fujitsu Ltd Optical waveguide and manufacturing method thereof
GB0126621D0 (en) * 2001-11-06 2002-01-02 Univ Nanyang A multimode interference (MMI) device
TW504593B (en) * 2001-11-29 2002-10-01 Ind Tech Res Inst Optical thermal-type waveguide switch
US6717227B2 (en) * 2002-02-21 2004-04-06 Advanced Microsensors MEMS devices and methods of manufacture
US6900510B2 (en) * 2002-02-21 2005-05-31 Advanced Microsensors MEMS devices and methods for inhibiting errant motion of MEMS components
US6858911B2 (en) * 2002-02-21 2005-02-22 Advanced Micriosensors MEMS actuators
US7035484B2 (en) * 2002-04-12 2006-04-25 Xtellus, Inc. Tunable optical filter
US20040005108A1 (en) * 2002-07-02 2004-01-08 Kjetil Johannessen Thermal compensation of waveguides by dual material core having negative thermo-optic coefficient inner core
US6987895B2 (en) * 2002-07-02 2006-01-17 Intel Corporation Thermal compensation of waveguides by dual material core having positive thermo-optic coefficient inner core
TW531671B (en) * 2002-07-22 2003-05-11 Delta Electronics Inc Tunable filter applied in optical networks
US6822798B2 (en) * 2002-08-09 2004-11-23 Optron Systems, Inc. Tunable optical filter
TWI229051B (en) * 2002-08-23 2005-03-11 Asia Pacific Microsystems Inc Movable inclined reflector based signal processing device and its method
US7085453B2 (en) * 2002-11-25 2006-08-01 Matsushita Electric Industrial Co., Ltd. Optical functional device and optical module
US20040145741A1 (en) * 2003-01-24 2004-07-29 Honeywell International Inc. Comb etalon fluid analyzer
US6925232B2 (en) * 2003-05-30 2005-08-02 Lucent Technologies, Inc. High speed thermo-optic phase shifter and devices comprising same
US7162120B2 (en) * 2003-07-18 2007-01-09 Nec Corporation Tunable dispersion compensator and method for tunable dispersion compensation
JP2007514961A (en) * 2003-10-07 2007-06-07 アイギス セミコンダクター インコーポレイテッド Adjustable optical filter with heater on transparent substrate with matching CTE
JP4409320B2 (en) * 2004-03-19 2010-02-03 日本航空電子工業株式会社 Variable optical gain equalizer and optical gain equalizer
GB2429791B (en) * 2004-04-09 2008-11-26 Optimer Photonics Inc Schemes for controlling optical signals in optically functional waveguide structures
US7447397B1 (en) 2004-06-14 2008-11-04 Dynamic Method Enterprises Limited Optical switch matrix
US7116463B2 (en) * 2004-07-15 2006-10-03 Optron Systems, Inc. High angular deflection micro-mirror system
US7442319B2 (en) * 2005-06-28 2008-10-28 Micron Technology, Inc. Poly etch without separate oxide decap
US20090322210A1 (en) * 2005-09-27 2009-12-31 Masahiro Yokoo Organic electroluminescent element substrate, and organic electroluminescent element and the manufacturing method
US8214157B2 (en) * 2006-03-31 2012-07-03 Nodality, Inc. Method and apparatus for representing multidimensional data
US8936404B2 (en) * 2006-05-09 2015-01-20 Alcatel Lucent Method, apparatus and system for self-aligning components, sub-assemblies and assemblies
US8821799B2 (en) 2007-01-26 2014-09-02 Palo Alto Research Center Incorporated Method and system implementing spatially modulated excitation or emission for particle characterization with enhanced sensitivity
US9164037B2 (en) 2007-01-26 2015-10-20 Palo Alto Research Center Incorporated Method and system for evaluation of signals received from spatially modulated excitation and emission to accurately determine particle positions and distances
US7633629B2 (en) * 2007-02-05 2009-12-15 Palo Alto Research Center Incorporated Tuning optical cavities
US7936463B2 (en) * 2007-02-05 2011-05-03 Palo Alto Research Center Incorporated Containing analyte in optical cavity structures
US7817281B2 (en) * 2007-02-05 2010-10-19 Palo Alto Research Center Incorporated Tuning optical cavities
US7852490B2 (en) * 2007-02-05 2010-12-14 Palo Alto Research Center Incorporated Implanting optical cavity structures
US7471399B2 (en) * 2007-02-05 2008-12-30 Palo Alto Research Center Incorporated Photosensing optical cavity output light
US8320983B2 (en) 2007-12-17 2012-11-27 Palo Alto Research Center Incorporated Controlling transfer of objects affecting optical characteristics
US20090180731A1 (en) * 2008-01-07 2009-07-16 Southern Methodist University Photonic coupler
US8373860B2 (en) 2008-02-01 2013-02-12 Palo Alto Research Center Incorporated Transmitting/reflecting emanating light with time variation
US8629981B2 (en) 2008-02-01 2014-01-14 Palo Alto Research Center Incorporated Analyzers with time variation based on color-coded spatial modulation
DE102009021936A1 (en) * 2009-05-19 2010-11-25 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Optical filter and a method for producing an optical filter
CN201518071U (en) * 2009-10-23 2010-06-30 昂纳信息技术(深圳)有限公司 Adjustable filter
JP2011227439A (en) * 2010-03-31 2011-11-10 Fujitsu Ltd Optical waveguide device, electronic equipment and manufacturing method of optical waveguide device
KR101063957B1 (en) * 2010-11-02 2011-09-08 주식회사 피피아이 The optical switch and the method of manufacturing the same using a silica waveguide with insertional polymer
EP2450734A1 (en) * 2010-11-03 2012-05-09 Sony Ericsson Mobile Communications AB Optical filter arrangement and a method for adjustment thereof
US8942267B2 (en) 2011-05-17 2015-01-27 Redshift Systems Corporation Thermo-optically tunable laser system
US8723140B2 (en) 2011-08-09 2014-05-13 Palo Alto Research Center Incorporated Particle analyzer with spatial modulation and long lifetime bioprobes
US9029800B2 (en) 2011-08-09 2015-05-12 Palo Alto Research Center Incorporated Compact analyzer with spatial modulation and multiple intensity modulated excitation sources
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CN106450635B (en) * 2016-12-08 2021-10-01 江苏贝孚德通讯科技股份有限公司 Integrated microwave waveguide coupler
GB2563405A (en) * 2017-06-13 2018-12-19 Oclaro Tech Ltd Tuneable filter
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04238305A (en) 1991-01-22 1992-08-26 Nippon Telegr & Teleph Corp <Ntt> Polymer-coated glass core optical waveguide
US5295011A (en) * 1990-06-25 1994-03-15 Siemens Aktiengesellschaft Optical duplexer for bidirectional optical information transmission
WO1995012828A1 (en) 1993-11-04 1995-05-11 Besse Pierre Andre Process for altering the intensity and phase ratios in multi-mode interference couplers
US5640474A (en) 1995-09-29 1997-06-17 The United States Of America As Represented By The Secretary Of The Army Easily manufacturable optical self-imaging waveguide
US5857039A (en) 1996-03-20 1999-01-05 France Telecom Mixed silica/polymer active directional coupler, in integrated optics
JPH1184434A (en) 1997-09-02 1999-03-26 Nippon Telegr & Teleph Corp <Ntt> Light control circuit and its operation method
US6243525B1 (en) * 1998-02-13 2001-06-05 Jds Uniphase Photonics C.V. Optical waveguide device comprising at least one bent waveguide channel

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3546620A (en) * 1967-01-26 1970-12-08 Us Navy Scanning fabry-perot laser "q" switch
US3666351A (en) * 1969-11-06 1972-05-30 Battelle Development Corp Controllable magnetooptical devices employing magnetically ordered materials
US3740144A (en) * 1971-11-22 1973-06-19 W Walker Method and apparatus for optically detecting the presence of an element in a substance
US3802775A (en) * 1972-09-05 1974-04-09 Us Navy Rapidly, continuously and synchronously tuned laser and laser detector
US4127320A (en) * 1977-06-29 1978-11-28 Bell Telephone Laboratories, Incorporated Multimode optical modulator/switch
US4679894A (en) * 1984-08-20 1987-07-14 Litton Systems, Inc. Electrically switched fiber optic directional coupler
US5173956A (en) * 1991-02-01 1992-12-22 Hughes Aircraft Company Thermally driven optical switch method and apparatus
JP3025982B2 (en) * 1992-01-21 2000-03-27 イビデン株式会社 Waveguide type optical directional coupler
US5212584A (en) * 1992-04-29 1993-05-18 At&T Bell Laboratories Tunable etalon filter
DE4312568A1 (en) * 1993-04-17 1994-10-20 Sel Alcatel Ag Optical hybrid switch
US5581642A (en) 1994-09-09 1996-12-03 Deacon Research Optical frequency channel selection filter with electronically-controlled grating structures
US5532867A (en) * 1995-06-06 1996-07-02 Hughes Aircraft Company Bias stabilization circuit and method for a linearized directional coupler modulator
JP2768320B2 (en) * 1995-09-04 1998-06-25 日本電気株式会社 Tunable optical filter
DE19549245C2 (en) * 1995-12-19 2000-02-17 Hertz Inst Heinrich Thermo-optical switch
US5915063A (en) * 1997-01-15 1999-06-22 Colbourne; Paul Variable optical attenuator
US5970186A (en) * 1997-03-11 1999-10-19 Lightwave Microsystems Corporation Hybrid digital electro-optic switch
US6144779A (en) 1997-03-11 2000-11-07 Lightwave Microsystems Corporation Optical interconnects with hybrid construction
US5862276A (en) * 1997-07-28 1999-01-19 Lockheed Martin Corp. Planar microphotonic circuits
EP0905546A3 (en) * 1997-09-26 2002-06-19 Nippon Telegraph and Telephone Corporation Stacked thermo-optic switch, switch matrix and add-drop multiplexer having the stacked thermo-optic switch
US6144780A (en) * 1998-10-05 2000-11-07 Lucent Technologies Inc. Polymer waveguide switch and method
DE19849862C1 (en) * 1998-10-29 2000-04-06 Alcatel Sa Thermo-optical switch has polymer light conductor with temperature control arrangement at coupling points with two optical glass conductors in parallel plane
US6311004B1 (en) * 1998-11-10 2001-10-30 Lightwave Microsystems Photonic devices comprising thermo-optic polymer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5295011A (en) * 1990-06-25 1994-03-15 Siemens Aktiengesellschaft Optical duplexer for bidirectional optical information transmission
JPH04238305A (en) 1991-01-22 1992-08-26 Nippon Telegr & Teleph Corp <Ntt> Polymer-coated glass core optical waveguide
WO1995012828A1 (en) 1993-11-04 1995-05-11 Besse Pierre Andre Process for altering the intensity and phase ratios in multi-mode interference couplers
US5640474A (en) 1995-09-29 1997-06-17 The United States Of America As Represented By The Secretary Of The Army Easily manufacturable optical self-imaging waveguide
US5857039A (en) 1996-03-20 1999-01-05 France Telecom Mixed silica/polymer active directional coupler, in integrated optics
JPH1184434A (en) 1997-09-02 1999-03-26 Nippon Telegr & Teleph Corp <Ntt> Light control circuit and its operation method
US6243525B1 (en) * 1998-02-13 2001-06-05 Jds Uniphase Photonics C.V. Optical waveguide device comprising at least one bent waveguide channel

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"4×4 Polymer Thermo-Optic Directional Coupler Switch at 1.55 μ m" Keil et al, Electronics Letters, IEE Apr. 14, 1994, vol. 30, No. 8 pp. 639-640.
"4x4 Polymer Thermo-Optic Directional Coupler Switch at 1.55 mu m" Keil et al, Electronics Letters, IEE Apr. 14, 1994, vol. 30, No. 8 pp. 639-640.

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6600848B2 (en) * 2000-08-02 2003-07-29 Corning Incorporated Integrated thermo-optical silica switch
WO2003016957A2 (en) * 2001-08-16 2003-02-27 Srinath Kalluri Index tuned multimode interference coupler
WO2003016988A1 (en) * 2001-08-16 2003-02-27 Scott David C Optical modulator with an index tuuned multimode splitter
US6618179B2 (en) * 2001-08-16 2003-09-09 Srinath Kalluri Mach-Zehnder modulator with individually optimized couplers for optical splitting at the input and optical combining at the output
WO2003016957A3 (en) * 2001-08-16 2003-10-30 Srinath Kalluri Index tuned multimode interference coupler
US6950596B2 (en) 2002-11-27 2005-09-27 Nec Tokin Corporation Variable optical attenuator
US20040101245A1 (en) * 2002-11-27 2004-05-27 Nec Tokin Corporation Variable optical attenuator
US20070147761A1 (en) * 2005-10-07 2007-06-28 Kwakernaak Martin H Amorphous silicon waveguides on lll/V substrates with barrier layer
US20130230320A1 (en) * 2012-03-05 2013-09-05 Alcatel-Lucent Usa, Inc. Flexible optical modulator for advanced modulation formats featuring asymmetric power splitting
US9369209B2 (en) * 2012-03-05 2016-06-14 Alcatel Lucent Flexible optical modulator for advanced modulation formats featuring asymmetric power splitting
US8867874B2 (en) * 2012-12-06 2014-10-21 Finisar Sweden Ab Method for modifying the combining or splitting ratio of a multimode interference coupler
US20140334775A1 (en) * 2013-05-07 2014-11-13 Sumitomo Electric Industries, Ltd Coherent mixer and 2x2 multi-mode interference coupler
US9366820B2 (en) * 2013-05-07 2016-06-14 Sumitomo Electric Industries, Ltd. Coherent mixer and 2×2 multi-mode interference coupler
JP7031082B1 (en) * 2021-06-04 2022-03-07 三菱電機株式会社 Semiconductor optical integrated device and optical integrated device
WO2022254687A1 (en) * 2021-06-04 2022-12-08 三菱電機株式会社 Semiconductor optical integrated element and optical integrated device

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NL1015055C2 (en) 2003-08-13
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US6449404B1 (en) 2002-09-10
US6535672B1 (en) 2003-03-18

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